path: root/Visual Basic

---
language: Visual Basic Console Application
contributors:
    - ["Brian Martin", "http://brianmartin.biz"]
filename: learnvisualbasic.vb

Module Module1

    Sub Main()
        'A Quick Overview of Visual Basic Console Applications before we dive in to the deep end.
        'Apostrophe starts comments.
        'To Navigate this tutorial within the Visual Basic Complier, I've put together a navigation system.
        'This navigation system is explained however as we go deeper into this tutorial, you'll understand what it all means.
        Console.Title = ("Learn X in Y Minutes")
        Console.WriteLine("NAVIGATION") 'Display 
        Console.WriteLine("")
        Console.ForegroundColor = ConsoleColor.Green
        Console.WriteLine("1. Hello World Output")
        Console.WriteLine("2. Hello World Input")
        Console.WriteLine("3. Calculating Whole Numbers")
        Console.WriteLine("4. Calculating Decimal Numbers")
        Console.WriteLine("5. Working Calculator")
        Console.WriteLine("6. Using Do While Loops")
        Console.WriteLine("7. Using For While Loops")
        Console.WriteLine("8. Conditional Statements")
        Console.WriteLine("9. Select A Drink")
        Console.WriteLine("50. About")
        Console.WriteLine("Please Choose A Number From The Above List")
        Dim selection As String = Console.ReadLine
        Select Case selection
            Case "1" 'HelloWorld Output
                Console.Clear() 'Clears the application and opens the private sub
                HelloWorldOutput() 'Name Private Sub, Opens Private Sub
            Case "2" 'Hello Input
                Console.Clear()
                HelloWorldInput()
            Case "3" 'Calculating Whole Numbers 
                Console.Clear()
                CalculatingWholeNumbers()
            Case "4" 'Calculting Decimal Numbers 
                Console.Clear()
                CalculatingDecimalNumbers()
            Case "5" 'Working Calcculator 
                Console.Clear()
                WorkingCalculator()
            Case "6" 'Using Do While Loops
                Console.Clear()
                UsingDoWhileLoops()
            Case "7" 'Using For While Loops
                Console.Clear()
                UsingForLoops()
            Case "8" 'Conditional Statements
                Console.Clear()
                ConditionalStatement()
            Case "9" 'If/Else Statement
                Console.Clear()
                IfElseStatement() 'Select a drink
            Case "50" 'About msg box
                Console.Clear()
                Console.Title = ("Learn X in Y Minutes :: About")
                MsgBox("Learn X in Y Minutes is a creation of Adam Bard (@adambard) This particular program tutorial is by Brian Martin (@BrianMartinn")
                Console.Clear()
                Main()
                Console.ReadLine()

        End Select
    End Sub

    'One - I'm using numbers to help with the above navigation when I come back later to build it.
    Private Sub HelloWorldOutput()  'We use private subs to seperate different sections of the program. 
        Console.Title = "Hello World Ouput | Learn X in Y Minutes" 'Title of Console Application
        'Use Console.Write("") or Console.WriteLine("") to print outputs.
        'Followed by Console.Read() alternatively Console.Readline()
        'Console.ReadLine() prints the output to the console.
        Console.WriteLine("Hello World")
        Console.ReadLine()
    End Sub
    'Two
    Private Sub HelloWorldInput() 'We use private subs to seperate different sections of the program. 
        Console.Title = "Hello World YourName | Learn X in Y Minutes" 'Title of Console Application
        'Variables
        'Data entered by a user needs to be stored.
        'Variables also start with a Dim and end with an As VariableType.
        Dim username As String 'In this tutorial, we want to know what your name, and make the program respond to what is said.
        'We use string as string is a text based variable.
        Console.WriteLine("Hello, What is your name? ") 'Ask the user their name.
        username = Console.ReadLine() 'Stores the users name.
        Console.WriteLine("Hello " + username) 'Output is Hello 'Their name'
        Console.ReadLine() 'Outsputs the above.
        'The above will ask you a question followed by printing your answer.
        'Other variables include Integer and we use Integer for whole numbers.
    End Sub
    'Three
    Private Sub CalculatingWholeNumbers() 'We use private subs to seperate different sections of the program. 
        Console.Title = "Calculating Whole Numbers | Learn X in Y Minutes" 'Title of Console Application
        Console.Write("First number: ") 'Enter a whole number, 1, 2, 50, 104 ect
        Dim a As Integer = Console.ReadLine()
        Console.Write("Second number: ") 'Enter second whole number.
        Dim b As Integer = Console.ReadLine()
        Dim c As Integer = a + b
        Console.WriteLine(c)
        Console.ReadLine()
        'The above is a simple calculator
    End Sub
    'Four
    Private Sub CalculatingDecimalNumbers()
        Console.Title = "Calculating with Double | Learn X in Y Minutes" 'Title of Console Application
        'Of course we would like to be able to add up decimals.
        'Therefore we could change the above from Integer to Double.
        Console.Write("First number: ") 'Enter a whole number, 1.2, 2.4, 50.1, 104.9 ect
        Dim a As Double = Console.ReadLine
        Console.Write("Second number: ") 'Enter second whole number.
        Dim b As Double = Console.ReadLine
        Dim c As Double = a + b
        Console.WriteLine(c)
        Console.ReadLine()
        'Therefore the above program can add up 1.1 - 2.2
    End Sub
    'Five
    Private Sub WorkingCalculator()
        Console.Title = "The Working Calculator| Learn X in Y Minutes" 'Title of Console Application
        'However if you'd like the calculator to subtract, divide, multiple and add up.
        'Copy and paste the above again.
        Console.Write("First number: ") 'Enter a whole number, 1.2, 2.4, 50.1, 104.9 ect
        Dim a As Double = Console.ReadLine
        Console.Write("Second number: ") 'Enter second whole number.
        Dim b As Integer = Console.ReadLine
        Dim c As Integer = a + b
        Dim d As Integer = a * b
        Dim e As Integer = a - b
        Dim f As Integer = a / b
        'By adding the below lines we are able to calculate the subtract, multply as well as divide the a and b values
        Console.Write(a.ToString() + " + " + b.ToString())
        Console.WriteLine(" = " + c.ToString.PadLeft(3)) 'We want to pad the answers to the left by 3 spaces.
        Console.Write(a.ToString() + " * " + b.ToString())
        Console.WriteLine(" = " + d.ToString.PadLeft(3)) 'We want to pad the answers to the left by 3 spaces.
        Console.Write(a.ToString() + " - " + b.ToString())
        Console.WriteLine(" = " + e.ToString.PadLeft(3)) 'We want to pad the answers to the left by 3 spaces.
        Console.Write(a.ToString() + " / " + b.ToString())
        Console.WriteLine(" = " + e.ToString.PadLeft(3)) 'We want to pad the answers to the left by 3 spaces.
        Console.ReadLine()

    End Sub
    'Six
    Private Sub UsingDoWhileLoops()
        'Just as the previous private sub
        'This Time We Ask If The User Wishes To Continue (Yes or No?)
        'We're using Do While Loop as we're unsure if the user wants to use the program more than once.
        Console.Title = "UsingDoWhileLoops | Learn X in Y Minutes"
        Dim answer As String 'We use the variable "String" as the answer is text
        Do 'We start the program with 
            Console.Write("First number: ")
            Dim a As Double = Console.ReadLine
            Console.Write("Second number: ")
            Dim b As Integer = Console.ReadLine
            Dim c As Integer = a + b
            Dim d As Integer = a * b
            Dim e As Integer = a - b
            Dim f As Integer = a / b

            Console.Write(a.ToString() + " + " + b.ToString())
            Console.WriteLine(" = " + c.ToString.PadLeft(3))
            Console.Write(a.ToString() + " * " + b.ToString())
            Console.WriteLine(" = " + d.ToString.PadLeft(3))
            Console.Write(a.ToString() + " - " + b.ToString())
            Console.WriteLine(" = " + e.ToString.PadLeft(3))
            Console.Write(a.ToString() + " / " + b.ToString())
            Console.WriteLine(" = " + e.ToString.PadLeft(3))
            Console.ReadLine()
            'Ask the question, does the user wish to continue? Unfortunately it is case sensitive. 
            Console.Write("Would you like to continue? (yes / no)")
            answer = Console.ReadLine 'The program grabs the variable and prints and starts again.
        Loop While answer = "yes" 'The command for the variable to work would be in this case "yes"

    End Sub
    'Seven
    Private Sub UsingForLoops()
        'Sometimes the program only needs to run once.
        'In this program we'll be counting down from 10.

        Console.Title = "Using For Loops | Learn X in Y Minutes"
        For i As Integer = 10 To 0 Step -1 'Declare Vairable and what number it should count down in Step -1, Step -2, Step -3 ect. 
            Console.WriteLine(i.ToString) 'Print the value of the counter variable
        Next i 'Calculate new value
        Console.WriteLine("Start") 'Lets start the program baby!!
        Console.ReadLine() 'POW!! - Perhaps I got a little excited then :)
    End Sub
    'Eight
    Private Sub ConditionalStatement()
        Console.Title = "Conditional Statements | Learn X in Y Minutes"
        Dim userName As String = Console.ReadLine
        Console.WriteLine("Hello, What is your name? ") 'Ask the user their name.
        userName = Console.ReadLine() 'Stores the users name.
        If userName = "Adam" Then 'Hey, if Adam uses this program, kudos where kudos is due, right?
            Console.WriteLine("Hello Adam")
            Console.WriteLine("Thanks for creating the useful tutorial site www.learnxinyminutes.com!")
            Console.ReadLine()
        Else
            Console.WriteLine("Hello " + userName) 'prints the username of the user 
            Console.WriteLine("Hope all is well have you checked out www.learnxinyminutes.com") 'Prints a message to the user
            Console.ReadLine() 'Ends and prints the above statement.
        End If
    End Sub
    'Nine
    Private Sub IfElseStatement()
    Console.Title = "If / Else Statement | Learn X in Y Minutes"
        'Sometimes its important to consider more than two alternatives. Sometimes there are a good few others.
        'When this is the case, more than one if statement would be required.
        'An if statement is great for vending machines. Where the user enters a code.
        'A1, A2, A3, ect to select an item.
        'All choices can be combined into a single if statement.

        Dim selection As String = Console.ReadLine 'Value for selection
            Console.WriteLine("A1. for 7Up")
            Console.WriteLine("A2. for Fanta")
            Console.WriteLine("A3. for Dr. Pepper")
            Console.WriteLine("A4. for Diet Coke")
            Console.ReadLine()
            If selection = "A1" Then
                Console.WriteLine("7up")
                Console.ReadLine()
            ElseIf selection = "A2" Then
                Console.WriteLine("fanta")
                Console.ReadLine()
            ElseIf selection = "A3" Then
                Console.WriteLine("dr. pepper")
                Console.ReadLine()
            ElseIf selection = "A4" Then
                Console.WriteLine("diet coke")
                Console.ReadLine()
            Else
                Console.WriteLine("Please select a product")
                Console.ReadLine()
            End If

    End Sub

End Module


```
## References

I learnt Visual Basic in the console application. It allowed me to understand the principles of computer programming to go on to learn other programming languages easily. 

I created a more indepth <a href="http://www.vbbootcamp.co.uk/" Title="Visual Basic Tutorial">Visual Basic tutorial</a> for those who would like to learn more. 

The entire syntax is valid. Copy the and paste in to the Visual Basic complier and run (F5) the program.